It is well known that interexaminer reliability is generally poor when it comes to diagnosing cervical somatic dysfunction using passive motion testing. Researchers at Michigan State University College of Osteopathic Medicine objectively measured cervical spine kinematics to determine why there is such variability in these findings with use of the standard manual osteopathic structural examination. This study, supported by funds from the American Osteopathic Association and the Osteopathic Heritage Foundation, sought to measure cervical spine kinematics using multiangle videography while experienced osteopathic physicians (ie, with 10 years of experience in osteopathic manipulative medicine) performed osteopathic manual diagnosis of somatic dysfunction in symptomatic volunteers with neck pain and in asymptomatic volunteers.

Forty-one volunteers participated in the study: 22 in the control group (mean [SD] age, 19.9 [1.9] years; 16 male, 4 female, 2 no response) and 19 in the experimental group (mean [SD] age, 27.5 [13.1] years; 14 male, 5 female). Volunteers in the control group were asymptomatic (ie, pain free) and had symmetrical findings on passive cervical lateral flexion (sidebending) motion tests as performed by a blinded, experienced examiner. Asymptomatic volunteers who had asymmetrical findings were excluded from the study. Volunteers in the experimental group reported a cervical pain score of 3 or higher on a 0- to 10-point visual analog scale. Blinded second and third experienced examiners performed the passive cervical range of motion (ROM) tests on participants in both study groups. Video kinematics assessed cervical ROM in lateral flexion, secondary rotations around the primary diagnostic motion of lateral flexion, and angular velocities.

Diagnostic cervical ROMs and secondary rotations were consistent for each examiner between trials for each study group, validating that examiners are reliable in gathering the same data repeatedly. In contrast, interexaminer comparisons for diagnostic cervical ROMs, secondary rotations, and average velocities yielded consistently larger measures for 1 examiner for both study groups (P<.05). This finding indicates that each examiner differs in how he or she examines a patient. Specifically, this study was able to quantify exactly how the 2 examiners differed. These objective data could potentially be applied to clinical decision making and could explain why 2 physicians may disagree on the diagnosis and treatment plan for the same patient.